Housing campaigners brought London traffic to a standstill yesterday as they emblazoned Tower Bridge with the words: “Social housing, not social cleansing.”

The banner-hanging stunt came 24 hours before today’s March for Homes, which is expected to see thousands swarm the streets of the capital.

“There is now no doubt at the depth of public concern about the capital’s housing crisis,” said Labour’s London Assembly housing spokesman Tom Copley.

“Rocketing prices and a lack of affordable supply have made housing the number one issue for many Londoners.”

The protest coincides with a Chartered Institute of Housing poll revealing that three-quarters of Londoners believe there to be a housing crisis in their area.

“With the average London home now costing over half a million pounds it’s crystal clear that for many Londoners owning a home is becoming little more than a dream,” Mr Copley added.

“Despite this, the mayor of London has consistently underdelivered, presiding over a boom in safety deposit-box homes for overseas investors while at the same time missing his affordable house-building targets.

“It’s time the mayor woke up to the scale of the problem.”

But Britain’s ever-rising rental costs also concern the campaigners.

According to new Office for National Statistics (ONS) figures, rents across the country rose by 1.7 per cent last year alone.

London was the region with the highest increase, with landlords now charging 2.4 per cent more on average.

Beloved housing campaigns such as Focus E15, New Era Residents and Defend Council Housing will be joined by students and activists on the march.

The Focus E15 Mothers said they were marching to “demand the building of council housing not luxury apartments.”

Half-empty estates such as the Carpenters Estate in Stratford should be reopened, they said.

The March for Homes was organised by protesters from south and east London — where housing shortages have been felt the most — and meet in front of City Hall.